Police officers in Daytona Beach are swabbing the mouths of persons of interests during traffic stops with special DNA kits in the hunt for an elusive serial killer, . . . . [T]he Daytona Beach police Chief, Mike Chitwood, said detectives have the killer's DNA. "Genetically, we know who he is," Chitwood said. "We have DNA evidence from the murder scenes — so, we got that. That is never going to go away. And, sooner or later, we will match the DNA to the physical person and bring closure to everything that is going on." Agents are using the DNA kits to collect as much DNA as possible during traffic stops and special operations in hopes on making a match. Local 6 showed agents stopping a person of interest from Canada, who gave his DNA to officers on the street using the DNA kit. The DNA kits are also being used in prostitution stings in the area.

Hey, wait, you're wondering — can they do that? The story is short on details, so it's kind of hard to tell. But here's some background on the law, which will explain how the legal issues might go depending on how the facts play out.

First, taking a DNA sample using a cheek swab is a Fourth Amendment search that would normally require a warrant. See Kohler v. Englade, 470 F.3d 1104 (5th Cir. 2006). It looks like the police don't have warrants here. The question then becomes if some exception to the warrant requirement applies to make the cheek swab reasonable. It may be that the officers are only asking targets for consent to give up a DNA sample. If that's the case, the swabs are constitutional under the consent exception. It also may be that the officers are only getting cheek swabs when they arrest someone. If that's right, the DNA samples are very probably constitutional under the search incident to arrest exception.

On the other hand, if they aren't waiting until they arrest targets; aren't making the tests voluntary; and don't have particularized warrants, then these swabs are very likely unconstitutional. (There's some possible issues of exigent circumstances or special needs, but I tend to doubt they would work out.)

Finally, it's worth flagging that I don't think the remedy is particularly clear in a case like this. Imagine an unconstitutional swab leads to a DNA match, and the target is then arrested. I gather that particular DNA match can't be used, as it's a fruit of the poisonous tree. On the other hand, I gather the police aren't blocked from trying to get a DNA sample some other way from the same guy, and since they know there's a match, presumably they would work hard to get another sample down the road anyway. DNA is not like a gun in someone's jacket pocket; it's always there, not just there at one particular time. It's not totally clear how the doctrine would work out, but presumably the police wouldn't just set the serial killer free — and presumably a court would let the government use another DNA sample taken another time in another way to prove the serial killer's guilt.

The DNA sample might show the person is related to the killer. If so, that could lead police to the real killer. A relative volunteering a sample probably has no idea that good old uncle Jack is a serial killer. Perhaps there are a dozen people in the area whose DNA would show a relation. Maybe someone knows if the tests can deliver this kind of information?

Is it true that if the police get an unconstitutional DNA sample, and realize they have the murderer, that they can then seek another, "proper," sample? Isn't the second sample fruit of the poisonous tree, since the police wouldn't have sought it but for the knowledge that came from the unconstitutional search?

Orin - what about the situation where these random people who give DNA do not match the murder suspect they are looking for but lo and behold DO match some other random unsolved crimes (maybe not even in the jurisdiction where the swab was taken). Does that change the outcome at all? I can imagine a guy who never committed a murder, but who has committed say a rape or something, agreeing (consenting) to a DNA swab "for a murder in Florida" and not realizing once they get his DNA it can be crossed against all kinds of databases and coming up positive in some investigation in say Texas.

I dont know if that would make a difference re unconstitutionality - but - it seems an argument could be made that consenting for a specific purpose (the murder) should limit the use of the dna to matching against that crime and that crime only. But once the DNA is given, the police will likely add it to another one of the expanding databases on all criminals who are sentenced to prison for felonies (which is what they do in my jurisdiction in IL) and who knows what could happen then.

I do know that consents are usually limited in scope to the express object of the search. For instance, if you consent to a search for drugs in your car, the police can look anywhere drugs may be found in the car. But they can't look in your house based on the vehicle consent alone, etc... Would the same principles apply re the swab for "a murder in Florida"? Any thoughts?

As a criminal defense attorney, my leaning is that the swab should be limited to testing against the specific murder alone and should then be destroyed. Im sure the police/state/fed gov't have other ideas.

DNA is not like a gun in someone's jacket pocket; it's always there, not just there at one particular time.

Given point #1, perhaps there is something wrong with this rule: "DNA samples are very probably constitutional under the search incident to arrest exception."

Search incident to arrest may have been mistakenly broadened. Its pretty clear that if you take someone into custody you need to search them for weapons. Thus any discoveries thereof are incident to the arrest, but the same can hardly be said of swabbing for DNA:

1) It doesn't pose a danger to the arresting officer. 2) It will still be there AFTER the police go to court to get an actual warrant.

Thus extending search incident to arrest to include DNA seems to be 1) non-obvious 2) unnecessary and 3) creates avenues of abuse.

Scary scary scary... The idea of the po-po pulling over random (or profiled, or even suspicious) drivers and making a DNA-swab-or-arrest offer (potentially based on a false threat of arrest) to build a permanent government catalog of DNA samples just about makes me want to put my tin hat on and start quoting Kafka.

well assuming the first swap is ruled unconstitutional..but then a second dna test convicts him...couldn't he bring a 1983 civil suit for the first swab even while in jail?

It's true that if something is found to be constitutional and not excluded at the criminal trial your barred from later suit in civil court under the claim that it was unconsittuional (Allen v. McCurry,
449 U.S. 90 1980)..but here he is convicted with different evidence and suing for the first dna swab which was (assuming again the court ruled as such and excluded the first swab) unconstitutional.

Joseph Wambaugh's The Blooding was an account of the first criminal case that used DNA to find the perp. It happened in England and the cops used some pretty heavy handed tactics to get a DNA sample from just about every male in the district. It took a while but they eventually got their guy.

But I think Orin is right it is constitutional if it is voluntary. I don't think it is, or should be, constitutional if the arrest is for an unpaid traffic ticket, or some other minor infraction. For one thing it would encourage the police to make unnecessary and unjustified arrests just to get a DNA sample. After all it is constitutional to arrest someone because their kids are not wearing a seatbelt. When the grounds are that flimsy for an arrest, then there are no meaningful restrictions on when the police can get a DNA sample.

Maybe the local 5-0 has been watching too much CSI: Miami - seriously, on that show they can get DNA from huge groups of people on a whim and have it all analyzed by the end of the next commercial break. As pro-cop as I am, this strikes me as a little creepy. I guess you could argue that taking DNA as part of an arrest is a lot like being fingerprinted, but perhaps there should be a provision to require that the data be expunged if the suspect is not ultimately convicted of some felony?

Well, isn't there the remedy for the many innocent people who are impacted by this to sue for damages for the unconstitutional action (assuming it's unconstitutional) and also suing to enjoin it? I mean remedies for unlawful police conduct are not, and should not, be limited to guilty parties.

I was going to note that this is done regularly in the various CSI shows. When those being tested complain, I remember the CSI investigators telling people that since it was a murder investigation, they could do it.

One interesting thing they do is sometimes find a partial match, indicating from the level of match the relationship between the person being tested and the perp. Oh, and then there was the guy who tested as a brother of the perp, but was actually the perp because he was a chimera, with DNA from two fraternal twins mixed shortly after inception.

Orin- If the police "work hard to get another sample down the road", that decision to work hard on the newfound suspect would presumably be direct result of the first DNA match, and seems to be fruit of a poisonous tree as a result.

Thre is vast room for abuse in this... but there is also room for awful errors.

DNA matching is NOT perfect... it is an X% match. Now, 99.8% might sound awfully good to you, but when you have the entire population of the US in your database (and, with the apparent ease of getting DNA samples for perpetuity from people, it's headed that direction quickly), 0.2% is several hundred thousand people.

DNA is a prtty darn good way of EXCLUDING people, and when you've already got suspects, that's very, very helpful... but it's not so good about INCLUDING people (that is, finding suspects in the first place), because it over-includes.

I would be interested in a post discussing the pros and cons of alternative remedies to Fourth Amendment violations like this. You mention that remedies are not clear; I am wondering what current thinking (academic or otherwise) is regarding the rights of someone like the swab-ee (the person who got swabed) to have his DNA expunged from the police's records (whether that person was a match for the killer or not). What worries me is not only that the police have invaded that individual's person by taking the unconstitutional swab, but that that individual's DNA will presumably remain on file forever. That, of course, is troubling.

Yeah, the victim of the unconstitutional cheek swab could probably win a 1983 suit. He'll get a $1 in nominal damages, which would probably be subject to forfeiture to pay any fines owed, or even for the cost of his imprisonment on some jurisdictions. What a great deterrent.

Prof. Kerr,

Under federal law, if you're caught going 36 in a 35 mph zone, or touching the center line on a left turn, or perhaps stop a little too far out on a stop sign, and the police want to test everyone's DNA, do they have basic carte blanche to do so given Supreme Court precedent that:

1) A traffic stop made for other law enforcement purposes is constitutional,

Assuming the arrest is allowed under state law (so Virginia v. Moore isn't implicated), this seems to be where we're going. But wait. Doesn't there have to be a special need to perform a strip search incident to arrest? If I'm correct, then it makes a lot of sense to say that the heightened privacy interest in one's bodily integrity that prevent routine strip serches incident to arrest after traffic violations would apply also to render routine DNA extraction of those arrested for traffic offenses also unconstitutional. What do you think?

As far as I know the Supreme Court has never required expungement of unlawfully discovered personal information about someone from a person's record, and given the relatively minimalist philosophy of the current Supreme Court, that isn't likelyto happen soon. I could be wrong, but I don't think that there's any case where somebody was unconsitutionally arrested, and then fingerprinted, where a court has thrown out use of the fingerprints to link the person to a later crime as the fruit of a poisonous tree. The courts would probably say that the connection is just too attenuated.

Perhaps you could further enlighten us on the following question: As a resident of Texas, I get pulled over for using a turn signal only 199 feet before the intersection. The cops want to search, but they don't feel like making an arrest. Since a search incident to a citation is unconstitutional they offer me the following choice- Consent to a search and get a citation, or we'll arrest you per Atwater on the violation and perform the search incident. The Hobson's choice induces me to consent, and contraband is found. Is the consent valid? If not, imagine the same scenario without the cops verbalizing what they in any event plan to do. They simply arrest anyone suspicious who doesn't consent to a search. The policy gets leaked to the public. Is there any federal remedy?

I hope they don't automatically arrest the first person who ends up being a purported DNA match. They should say nothing, do nothing, and INVESTIGATE that individual to find real evidence that he/she is the serial killer. There may be several people with the same DNA match in the world, depending on how they're doing the DNA testing. The cops should not be lazy here, they should do their job and investigate -- a DNA match would just be a lead, not conclusive evidence of guilt.

Also, the fact that they're using traffic stops to go after "persons of interest" implies to me, at least, that they are making unlawful, pretextual traffic stops to request consent for a search (of the individual). Why not call these people, or go to their homes, and speak with them and ask for a DNA swab? Why do it in a traffic stop which sure seems to me to be unlawful?

I was going to note that this is done regularly in the various CSI shows. When those being tested complain, I remember the CSI investigators telling people that since it was a murder investigation, they could do it.

In my experience, TV crime shows are not the best means of learning about 4th Amendment law, or any other branch of law for that matter.

Constitution Shmonstitution. If a scientifically sound but unconstitutionally taken DNA test matches a suspect to a series of murders, there are probably two judges in the entire country with the integrity to throw it out.

This is truly an academic discussion. But then again, Professor Kerr is an academic.

In 1999, in Philadelphia, Robert Jackson was sent to prison for murder based on fingerprint evidence. It was later overturned because of a "misidentification".

That is just a single example. I don't want my fingerprints, or my DNA, getting into any law enforcement system so that I can be "misidentified" like that. That's really the bottom line. If you don't have reason to suspect that person ( as would be shown by a warrant ), then you don't have any business swabbing them.

A simple doctrinal question for people who know about these matters: if the police ask for consent to take a swab, and the person refuses, can the police use that refusal as a basis for probable cause for a warrant?

A simple doctrinal question for people who know about these matters: if the police ask for consent to take a swab, and the person refuses, can the police use that refusal as a basis for probable cause for a warrant?

It is a good question since implied in the concept of "voluntary" is the idea that one is free to refuse--which means free to refuse without consequences. However, as you may have read in the thread, the police can give you the option of consenting or being arrested for a 'legitimate" but trivial and pretextual traffic violation. I'd like to know if that route would be legal, as has been asked earlier.

Help me understand the extent of the poisoning from the fruit of the tree concept.
It would seem that learning the exact identity from illegally acquired DNA would almost completely immunize this guy. Since they know it's him through improper means, they cannot use this knowledge to stake out his garbage and find a soda bottle with his DNA on it.
They would have to 'learn' his identity from some completely independent means, and be able to prove that they would have learned it even if they did not have the advantage of knowing who precisely they were looking.

It doesn't. In fact, even 99.99% sounds _very_ dodgy to me if the pool of potential persons of interest is as large as I suspect it is. What are the chances that the average police officer, prosecutor, or juror has a firm understanding of Bayes's Theorem? Only about 50% of MDs get concrete questions about it right.

Leaving aside questions of law, this sort of search is not useful unless there is a _vanishingly_ small chance of a false positive or you can restrict the potential pool to a small number of persons of interest. The idea that you might start looking at people's relatives based on a swab at a random traffic stop is frightening. I suppose you might as well try to teach a lemur to do differential equations as try to explain this to a law officer. That's one reason it's important to restrict their power to search.

Respondent: you're right, I was sloppy with my language. I meant to say they were making stops without reasonable suspicion or probable cause to get a dna swab. Or is it really true that everyone is violating at least one traffic law and thus can be lawfully stopped at any time?

It sounds like you folks want to make it as hard as possible to get a conviction (maybe you all live in safe neighborhoods). How about facial features? is it legal for me to wear a mask (or a veil)? can police force me to remove a mask and reveal myself in a lineup? I'm sure the answer is yes. Is that not a search? what's the basis for it? just my clothes? just because I was in the area?

Explain the difference. The DNA match is at least nearly accurate. Witness identification is (arguably) unreliable. (some of) You folks want to toss out the most reliable evidence available. I agree with PC. Do we want to solve crimes or create interesting games?

Joseph Wambaugh's The Blooding was an account of the first criminal case that used DNA to find the perp.

That was an excellent account of the first large scale DNA crime screening. I couldn't remember the title until Kazinski mentioned it - but I still recall the perp's name: Colin Pitchfork. Fitting name, huh? You can almost smell the sulfur fumes.

And they got him because he was about the only guy that wouldn't give his DNA [he talked someone else into pretending they were him.] So even a legitimate refusal to cooperate would probably put you on the list of possible suspects.